1. Field of the Invention
The present invention relates to a forming fabric for use with a machine for the production of a fibrous web material, and, more particularly, to a forming fabric used in a papermaking process, for example, in a forming section of a papermaking machine.
2. Description of the Related Art
In the production of a fibrous web material, such as paper, it is generally required that a fine structuring be present in the web material contact side of a fabric belt. That is to say, the side that the fibrous web material is in direct contact with should have a fine structuring in order to avoiding any marking effects. The desirable property on the wear side or machine side of the fabric belt is such that wear and abrasion should be reduced as much as possible so that the machine side, which is in contact with various rollers for deflecting and advancing the web material should be configured to keep wear and tear to a minimum.
A composite fabric for papermaking machines is known from European Patent Application No. EP 0 432 413 A1, wherein two fabric layers are on top of each other, having two transverse threads arranged directly on top of each other is described. The number of transverse threads of the layer on the paper side corresponds to the number of transverse threads of the layer on the machine side of the fabric. Threads extending in the longitudinal direction of the fabric are incorporated to both fabric layers, and alternate on the crossing points between both fabric layers in order to create a structural connection between the layers.
In International Publication No. WO 2006/020414 A1, there is disclosed a fabric for a paper machine, having two fabric layers positioned on top of each other including warp and weft yarns. The number of weft yarns in the fabric layer on the paper side is twice as high as the number of warp yarns in the fabric layer on the running or machine side.
In International Publication No. WO 2004/085740 A1, there is disclosed a fabric belt for a papermaking machine, wherein the connection between two fabric layers is carried out by way of warps that are structurally incorporated and alternating at crossing points between the fabric layers. The fabric layers further include layers of weft yarns, wherein the number of weft yarns in the fabric layer on the paper side is twice as large as the number of weft yarns in the fabric layer on the running or machine side.
A fabric belt for a paper machine is also known from European Patent Application EP 1 605 095 A1, wherein both fabric layers are embodied with threads extending in the longitudinal belt direction, wherein the number of threads in the fabric layer on the running side is twice as large as that in the fabric layer on the paper side. The connection of both fabric layers is carried out by way of the structurally binding threads extending in the longitudinal direction and transfer threads alternating between the fabric layers.
What is needed in the art is a forming fabric for machines for the production of a fibrous web material that has a high degree of wear resistance and increased seam strength.